I have been reading over on the powerequipment forum, generator forums and just learned in the last couple of days that the Honda GX620 v twin on my big generator has two drain plugs. Years ago I had installed a fumoto drain valve with a nipple for a drain hose, makes oil change much cleaner as no oil drains or drips on the frame. I finally found tread size and ordered a magnetic drain plug for the other size( It is somewhat hidden behind some of the wiring. That plus a magnet on the oil filter should help a good bit. I also have a pressure washer with a much smaller Honda GX200, splash lubed engine. It has a drain plug that also was replaced with one of the fumoto valves and extension hose. It has a oil filler cap. I looked and looked for thread size on the cap and finally found two different sizes shown, then having changed the oil in it today, got to thinking, went back out, pulled it out and got one of my little Honda EU2000 generators out, which have had a magnetic dipstick cap installed since day one and tried in in the pressure washer and it works, so ordered another one to install in the washer.